1.Field of the Invention
The present invention relates to injectable preparations containing a cephalosporin medicament, which can be used effectively in the field of medicines.
2.Description of the Related Art
A cephalosporin represented by the following formula: ##STR2## namely, 7.beta.-{2-(5-amino-1,2,4-thiadiazol-3-yl)-(Z)-2-fluoromethoxyiminoacetami do}-3-{( E)-3-(carbamoylmethylethylmethylammonio)-1-propen-1-yl}-3-cephem-4-carboxy late and pharmaceutically acceptable salts thereof (hereinafter called "the above substances" for the sake of brevity) have a broad antibacterial spectrum ranging over Gram positive bacteria, Gram negative bacteria and anaerobic bacteria. In particular, they are highly useful cephem-series antibiotics capable of exhibiting strong antibacterial activities against resistant Staphylococcus and Pseudomonas aeruginosa and are expected to have utility as injections (Japanese Patent Application Laid-Open No. 156984/1989).
The above substances are however accompanied by the drawback that they are unstable and are susceptible to decomposition under high-temperature and/or high-humidity conditions, leading to content reduction and coloration.
Conventional stabilization methods for cephalosporin derivatives include the method disclosed in Japanese Patent Application Laid-Open No. 216996/1989 and the pharmaceutical preparations disclosed in Japanese Patent Application Laid-Open No. 37728/1986. According to the method, lactose, glucose, sucrose or galactose is added along with glycine to a cephalosporin derivative, followed by lyophilization. Each of the pharmaceutical preparations comprises ceftazidime, sodium carbonate and amorphous lactose. Neither the method nor the pharmaceutical preparations are however satisfactory to stabilize the above substances.